From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 956AAC433F5 for ; Wed, 8 Sep 2021 14:35:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 75A7A6113D for ; Wed, 8 Sep 2021 14:35:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232812AbhIHOg7 (ORCPT ); Wed, 8 Sep 2021 10:36:59 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:36663 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231164AbhIHOg5 (ORCPT ); Wed, 8 Sep 2021 10:36:57 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631111749; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=fyCvOUubu5V5znnFPKMe78BgdN44gDtOtp7gcKdSn+c=; b=a3GVQrDHqvh7bsrS2tvFuZrsz7OuflkJ2j/EDw3lXE8AxepeZNpI7LYazoyXvtpE8OL0Uu qkhU6jq06E9kc95fyjaYaGCHVXw2tAvppi73Id3u61iStra/9/xwNcLhQA2Zt0Cw/zB4VI rqeeWqlhEHGaIHlHpeaTu4ZnJRhCjzY= Received: from mail-qv1-f72.google.com (mail-qv1-f72.google.com [209.85.219.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-243-Ri9WKvsMP8eSSjJ4or1A5A-1; Wed, 08 Sep 2021 10:35:48 -0400 X-MC-Unique: Ri9WKvsMP8eSSjJ4or1A5A-1 Received: by mail-qv1-f72.google.com with SMTP id r18-20020a056214069200b0037a291a6081so1145468qvz.18 for ; Wed, 08 Sep 2021 07:35:48 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:subject:to:cc:references:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=fyCvOUubu5V5znnFPKMe78BgdN44gDtOtp7gcKdSn+c=; b=vK/7Ilya2cFTy31BphUpeuX7tC4n3DDSCOOiLYPUqXuNGrErI+x1jBH9UZa3ZNZY/a z/npIjh3JasBo3cP4r7sE61N0nlAppDAZC9dZhGq9sL0XtD11j16sOYj35XQlGdpDgAQ dbFLmJYLhYr25M3iiDUXri29ld3uyEbxCeIfZZQMq54qb8CfncaoDQL4MPX8UaSvEYHk m8iIiDKvRoH8gTTHc5ZZiLGyq7Ay/5gfSF8MTNpbK97JoaDRxd9kiFhk/GJMUoFAHcgO K/t12wuJJqCAqt8UDK1ipVdSGvqBBDNHswTnkydL7IxTDOgj2SCPjAgOgV6jvmQM8dmJ p/gw== X-Gm-Message-State: AOAM5316sS36isvDG5LTZmlf/XqrLWyJHEDlQK2EyaozdN3kSt80syQJ FJSEFFfFhiOI5QnwKSg500v26HRa/EIzAUFNCf9TGr+8dJkGDGkgMfLemTswTzbtAmKD2tB+pDX tl0EQtozWhyyq4gzeJKhLwvUo X-Received: by 2002:a05:622a:1347:: with SMTP id w7mr3886378qtk.325.1631111748010; Wed, 08 Sep 2021 07:35:48 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzthtc49bvVEAvQLoKrGXyPvuVdLihAb/JCbXUGSNxHx+kK7a/jyb0auYu1qctCYiPjc7j9BQ== X-Received: by 2002:a05:622a:1347:: with SMTP id w7mr3886360qtk.325.1631111747794; Wed, 08 Sep 2021 07:35:47 -0700 (PDT) Received: from llong.remote.csb ([2601:191:8500:76c0::cdbc]) by smtp.gmail.com with ESMTPSA id j9sm1498712qta.65.2021.09.08.07.35.46 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 08 Sep 2021 07:35:47 -0700 (PDT) From: Waiman Long X-Google-Original-From: Waiman Long Subject: Re: [PATCH v2] lockdep: Let lock_is_held_type() detect recursive read as read To: Sebastian Andrzej Siewior , Waiman Long Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , Ingo Molnar , Will Deacon , Boqun Feng , Thomas Gleixner References: <20210901162255.u2vhecaxgjsjfdtc@linutronix.de> <9af2b074-9fcf-5aea-f37d-9b2482146489@redhat.com> <20210903084001.lblecrvz4esl4mrr@linutronix.de> Message-ID: <6bfddae4-dd66-b105-480f-ad4fe5c03276@redhat.com> Date: Wed, 8 Sep 2021 10:35:46 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210903084001.lblecrvz4esl4mrr@linutronix.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9/3/21 4:40 AM, Sebastian Andrzej Siewior wrote: > lock_is_held_type(, 1) detects acquired read locks. It only recognized > locks acquired with lock_acquire_shared(). Read locks acquired with > lock_acquire_shared_recursive() are not recognized because a `2' is > stored as the read value. > > Rework the check to additionally recognise lock's read value one and two > as a read held lock. > > Fixes: e918188611f07 ("locking: More accurate annotations for read_lock()") > Signed-off-by: Sebastian Andrzej Siewior > --- > v1…v2: > - simplify the read check to !!read as suggested by Waiman Long. > > kernel/locking/lockdep.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > --- a/kernel/locking/lockdep.c > +++ b/kernel/locking/lockdep.c > @@ -5366,7 +5366,7 @@ int __lock_is_held(const struct lockdep_ > struct held_lock *hlock = curr->held_locks + i; > > if (match_held_lock(hlock, lock)) { > - if (read == -1 || hlock->read == read) > + if (read == -1 || hlock->read == !!read) > return LOCK_STATE_HELD; > > return LOCK_STATE_NOT_HELD; > Thanks for accepting my suggestion. Acked-by: Waiman Long